The Free State was annexed by Belgium in 1908 as the Belgian Congo.

[1] The Congo-Kasaï province was split into Léopoldville and Lusambo (Kasai), the number of districts subsequently reducing to 15.

It covered essentially the same territory as the present Kwilu Province.

Bandundu Province was formed in 1966 by merging Kwilu, Kwango and Mai-Ndombe.

[7] As of 2008 Kwilu District contained the territories of Bagata, Bulungu, Masi-Manimba, Gungu and Idiofa.